Anti-fouling protective coating compositions



3,333,809 Patented May 8, 1962 this invention will be readily appreciated as the same 3,033,809 becomes better understood by reference to thefollowing COATING detailed description. y p I John R. Saroyan, 1320 Carl Ave, Vallejo, cast, and TE? P i t Hing D. Dear, 535 Grant Ave, San Francisco, Calif. 5 130.51 on a e W1 cop P rosin (a cycle N0 Drawing Filed 5m. 29, 1966, San N0. 5566 acid) and a high molecular weight polyisobutylene clas- 7 Cl 1 260.437 tomer known commercially as Vistanex (Enjay Co.). (Granted under Title 35, US. Code (1952), sec. 266) It has been found that difierent grades of Vistanex can be employed with very little difference in the final proper- The invention described herem may be manufactured 10 ties Of the composition; Vistanex 10 is preferred, but and used by for theGol/Emmem of the Unitlid Slates of Vistanex 13-80 and B-120 yield excellent results. America for governmental purposes without the payment of any royalties thereon or therefor. I I j The present invention relates to a coating composition and more particularly to an anti-fouling protective coating 5 Table I below represents various formulations made to explore the effects of various proportions of Vistanex, copper pigment, rosin and paint thinner:

composition. w The present invention is directed to the productionof I Table I an improved anti-fouling paint which, in addition to meet- [Ingredients in pounds/100 gals. intl l ing better the broad application of anti-fouling paints, has

a superior capability for meeting the more stringent rc- Formula Pyro Elec. 2 cement Vlstanex Rosin P. quirements of an anti-fouling compositionlto be used on out) GU20 copper 3:100 thinner rubber sonar domes. Such a composition for rubber V sonar domes is required, in addition to its anti-fouling 22% fig property, to provide high degrees of flexibility, adherence 5s: 5 80:0 "502 and durability and sufficient sound-transparency. Out- 2%} 25-2 gig standing in the present composition are the high degree of 44: 5 3012 '559 flexibility of and the high concentration of toxicity in the gg'g 28': 12% resulting film. The best previously-available antidouling 3912 46:5 49s composition for such surfaces was Navy Standard 15 NRL fig whose principal ingredients comprised a combination of 3018 [5419 399 elastomer, mercurous chloride, copper resinate, titanium 383 if? 222 dioxide and diatomaceous silica; this composition has cer- 42:4 7, 0' 552 tain disadvantages among which are that it is deficient in g'g 8'' Egg anti-fouling properties and is dilficult to control, being 38:5 80.0 502 susceptible to hard pigment settling. gig 38:2 223 The fundamental concept of the present invention is 41.7 29.7 524 portrayed by the mixture of copper pigment with high 22'? 28-; 23 polymer polyisobutylene elastomer and a cyclic acid. :6 70:4 462 Composition grounded on these ingredients shows exem- 524 plary flexibility and adhesion on rubber, proper sounflt transparency and excellent fouling resistance, The pigment suspension attained iS eXcellfillt, obviating the 'difi- 3 Oopper-cuprous oxide pigment. culty in that regard present with Navy Standard 15 NRL.

Like all anti-fouling paints the portraitive composition of loalcd. parts by volume in dry film] copper pigment, cyclic acid and a high molecular weight v polyisobutylene elastomer is formulated with a high p' er- Formula No. C1120 Vlstanex Rosin centage of the toxic ingredient, ifeijthe copper pigment. Since it is well known that copper has a deleterious actiEn 45 10 45 on rubber, especially on the type of, natural rubber com= 12 $8 monly used in sonar equipment, the present invention co'n- 45 25 30 templates the use of suitable primers on the rubber in 'a 2g 2g V 33 paint system wherein the anti-fouling composition is ap- 10 30 plied over the primer-rather than directly to the rubber. 28 An object of the present invention is the provision ofan 2g 2g lg improved anti-fouling protective composition. 10, 15 Another object is to provide an anti-fouling protective 75 15 10 composition suitable for application on rubber surfaces. f A further object is the provision of an anti jfouling pro- 32 i2 3 tective composition suitable for application on sonar 2O 35 domes 45 35 20 An additional object is the provision 0d. an anti-fouling 23 protective composition suitable for application on rubber 2g sonar domes. 60 15 25 Still another object is to provide primers suitably aug- 60 25 15 menting the anti-fouling composition in a paint system. 35

Another Object is to provide primers suitably augment- Norn4ll paintscontain from .06 to .09 lb. Deenax staillg the anti-fouling composition in a paint te applb blllzer (En ay C0. dl-ter-butyl P cresol).

cable to rubber surfaces.

A further object is to provide prirners suitably aug- In addition to cupfous Pxide and n'letauic pp menting the anti-fouling composition in a paint system 7 p gmentother compounds WhlCh can provide the toxicity a li bl t rubbe sonar domes, which gives the-composition its anti-fouling property are Other objects and many of the attendant advantages of suitable ingredients for this composition. Typical of these 1menta Table IV ANTIFOULING PAINTS Table IV below is an analysis of the pigment sed tion characteristics of these different formulations:

PIGMENT SEDIMENT IN POLYISOBUTYLENE PAINTS STORED IN QUART CANS FOR TWENTY MONTHS ment-rosin-Vistanex composition obviates the control difliculty incurred with prior anti-fouling compositions 75 such as Navy Standard 15 NRL.

Table II Table 11 below is a summary of test results of these various formulations and of comparative test results of Navy Standard 15 NRL.

are certain mercury compounds, such as mercuric oxide and mercurous chloride, for example.

SUMMARY OF RESULTS OF TEST N POLYISOBUTYLENE 6 S f S m "m W wfi mowucmoa W9 u ri L d. w o 7 Prh 54 1 Wm B t 9 P e rd sd r at m M h o dm e .r w 0 ed 8L c m wm a m .m m s n 989904016579513481517139881321082 d '1 r 1 a mmv. mmmmmmmnnnnmnmmmmmmmm mmummmn m w m m e m g m P e t n m P we 0 h $5 3. W m a m m0 t g n t m u pm m o n e i 1 smo mmm mw mmmmmm mwwmwmmw m m mmmm mm H m z m a m m m Mmmm m mm mm d 0 e f Re. arm s w mwi m m 0 n B3 h .1 6 ,us i l f n mm wws MR mw wmw mmu wwmwwwmm ww mm B AM n B m m wmvt. min" 0 .w S fin S1 1 r .u T. s nte uni, e P 0 na t o n be & aa U e n 0 b a n 7 p a-.. ce 2 afFf. m 3 e 0 e 0 av p .f 141942334574534654275819151892246 :Vilgh I H m m d Q 0 W. C 7 S kolt. zm a n a e e r u m amm aiLauoaLLLnlzzLaiuuuoiLZZLZLlLLLZ m wm M N N m e 0 s m m M W U s e 0 .1 r. e g t I U a H .L Tm mmww hb omv h F .1 n S .W. e g e 6 C O S W 8 n lama wwom ow a h dm t m i w am w ofie nw o e e wm at m as? muev y edn s m me so m 3 mama iawmm a i wawm m m mrsb e o0 e t. e I q 6 a e m i o m in cw d i rsh n0 d g v. n dme e md S SD 0 I1. 1 a p d I a v .19 tvnf. lt S O S e O. a 1 8. F5 m eww R n e W e .mW m mu w m a 3mm aom mmwmmtwv m m mm m m .1 a t 1 tf g a .1 n t ma l m mnnmvn aa.1P s i a anuO lo w 8 6 LS Omamo m m wimmm m w v uP mim swmw w VRmP m e I n h W ohmfic n a n .II mama m o P wfi ano d P F Laaiaazasmnmmm m m u a N V ud, m o a Pm N V 0 5 0 0 5 0 5 0 5 0 1 1 2 4 4 5 5 6 6 7 i an i a N t m .m S h I .m wm wml C L W .mb .m 1. U r D o mm a o 0 a a w. m o w H m moo do u awwiw m w a w 44 32114432145455451111555544553335 BM WF T H .ZDD DD D Dmfl w m mfi xm m n N w m m 0 m n w a em .w m A C NC N 0 NC N w 3 fi m E 1 m m w N u h n u u n LU/ t '1 g e n E n m g 2234432111221112152322.2322 2 m2 2 N w m. m n m m M. n m m m me Wm or 3 m d z m Tm ma n :ma m N( mm mm smHmm m mum n u :mm m 5 8 00 0 m .1 mm m Wmkmm P mum m m a. m m m P t .1 ..m n m 113444211122111115111111111 111 1 2 f m 1% A C F u C n n u. F1 F E0 1 10 m TLP A a n r e 0 n 5 5 s m m mm m m m P mm mma w mm m mnwam mmawam R a a M Sam F On or P F1 5.1 .1. 0 MW 1 r {L d PS 7 u n mm m s We Y m J u ee w m T 0 u im IW1 6 I N N. DIM bf L a L fr H o r 0 m e B3 I S m N mm m m s 6 m S a o wmmm a m m m F nun 3 a m ssmsaa T.@ w m 4 1 C T. L MB m1 ml 3 D 9 3-120 represents Formula #3 using Vistanex B420 instead of B-lOO. Like variation of the various Formulas 8, 10, and 13 follows.

3-80 represents Formula #3 using Vistanex B-80 instead of B-iOD. Like variation of the various Formulas 8, 10, and 13 follows.

Other solvents may be employed in place of the paint thinner. Typical examples are xylene and mineral spirits.

A recommended formulation procedure is as follows:

Add all the polyisobutylene resin (cut up into small pieces) and any inhibitor employed to nearly all the solvent to form a 7.5% resin solution. Unlike rubber, polyisobutylene resin should not be masticated before preparing the solution, as this causes degradation with resulting deterioration of mechanical properties. If rolls are used to draw the resin out in thin sheets before introduction into the solvent, mastication of the resin should be held to the very least possible amount, and the rolls should be held to about 150-200 degrees centigrade. Solution of the resin is a slow swelling process relatively independent of the rate of agitation. The minimum agitation which prevents settling and compaction of the resin is recommended. The cuprous oxide pigment is mixed with a portion of the 7.5 resin solution to make a mill paste which is then ground on a roller mill. The rosin is dissolved in the rest of the. solvent. The mill paste, rosin solution, and rest of the 7.5% resin solution are blended to form the finished paint.

It is a well known fact that copper has a deleterious action on rubber. Accordingly, because of the high copper pigment content of the anti-fouling composition, the invention further contemplates use with the anti-fouling composition, particularly directed to the application of the composition on rubber sonar domes, of supplemental primers. The primers, being applied to the rubber surface first, tend to insulate it from the copper pigment and its deleterious efiect thereon.

Illustrative of the paint system incorporating the antifouling composition and primers are the following coatings which are applied to the to-be-coated surface in the sequence in which they are below-listed:

(1) One coat MIL-P-5054, clear elastomer paint.

(2) Three coats RP-151, polyisobutylene primer.

(3) Two coats anti-fouling composition, preferably Formula #10.

The first primer (MIL-P-5054) may consist of any elastomer primer suitable for rubber. Examples are clear elastomer paint manufactured by Akron Paint and Varnish Company, and Gaco N-29 (neoprene cement) manufactured by Gates Engineering Company. The clear elastomer is a natural rubber solution with a colorless pigment. A variety of natural rubber solutions or cements would be suitable. This first primer as a coating on the rubber also acts to increase the adhesion of the polyisobutylene paints.

The polyisobutylene primer (RP151) serves as an excellent undercoat since it is flexible, adheres readily to rubber, and has good compatibility with copper-loaded paints. The following is an illustrative example of the composition of this primer.

Ingredients: Gallons per 100 gallons Carbon black pigment 1.90 Polyisobutylene resin, Vistanex 13-100 4.38 Petroleum spirits (solvent) 93.72 Inhibitor (Deenax; Enjay Co.) .004

The recommended formulation process for the polyisobutylene primer (RP-151) is as follows:

Add all the polyisobutylene resin (cut up into small pieces) and inhibitor to a portion of the petroleum spirits to form a 7.5% resin solution. Unlike rubber, polyisobutylene resin should not be masticated before preparing the solution, as this causes degradation with resulting deterioration of mechanical properties. If rolls are used to draw the resin out in thin sheets before introduction into the petroleum spirits, mastication of the resin should be held to the very least possible amount. Solution of the resin is a slow swelling process relatively independent of the rate of agitation. The minimum agitation which prevents settling and compaction of the resin is recommended. Charge one-third of the prepared 7.5% resin In addition to their other characteristics both of the aforementioned primers are sufliciently sound-transparent to supplement the anti-fouling composition in a paint system suitable for use on rubber sonar domes. These paints dry to a dense non-porous coating which readily transmits sound.

The specific formulations for the anti-fouling composition set forth above have included rosin as the cyclic acid ingredient. The ingredient is broadly defined by a cyclic acid capable of exhibiting dissolution in sea Water. Within this group cyclic acids of unusually high molecular weight, e.g., 500 or greater, are not practicable because of their excessive dissolution rate in sea water. Suitable cyclic acids, in addition to rosin, are the resinous acids hydrogenated rosin and abietic acid and naphthenic acid (not a resinous acid). When this ingredient is present in zero amount, as in Formula #15, for example, the amount and placement of the toxic element, e.g., copper, is such that there is a continuous contact of toxic particles so that where one is dissipated in the anti-fouling action another is immediately available for reaction with the fouling matter.

The Vistanex in the specific examples portrayed a polyisobutylene polymer with molecular weight of at least 80,- 000 and in the preferred B had a molecular Weight of 100,000.

()bviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. An anti-fouling protective coating composition comprising, by weight, non-volatile ingredients comprising from about 82% to about 97.5% cuprous oxide, from about 1.7% to about 10.5% polyisobutylene polymer of molecular weight from about 80,000 to about 120,000, from 0% to about 15% rosin, and volatile ingredients comprising a solvent of from about 20% to about of the non-volatile ingredients.

2. An anti-fouling protective coating composition comprising, by weight, non-volatile ingredients comprising from about 82% to about 97.5% cuprous oxide, from about 1.7 to about 10.5% polyisobutylene polymer of molecular weight of about 100,000, from 0% to about 15 rosin and volatile ingredients comprising a solvent of from about 20% to about 130% of the non-volatile ingredients.

3. An anti-fouling protective coating composition comprising, by Weight, non-volatile ingredients comprising from about 82% to about 97.5% cuprous oxide, from about 1.7% to about 10.5% polyisobutylene polymer of molecular Weight of about 100,000, from 0% to about 15% rosin and volatile ingredients comprising paint thinner of from about 20% to about 130% of the non-volatile ingredients.

4. An anti-fouling protective coating composition comprising, by weight, non-volatile ingredients comprising about 90% cuprous oxide, about 5.9% polyisobutylene polymer of molecular weight of about 100,000 and about 4.1% rosin and volatile ingredients comprising a solvent in the amount of about 73% of the non-volatile ingredients.

5. An anti-fouling protective coating composition comprising, by weight, non-volatile ingredients comprising 90% cuprous oxide, 5.9% polyisobutylene polymer of 42% paint thinner, 2.4% rosin, and 52.2% cuprous oxide.

7. A coating composition comprising, in percentage by volume in the dry film thereof, 60% cuprous oxide, 25%

polyisobutylene polymer of molecular weight of 100,000, and 15% rosin.

References Cited in the file of this patent UNlTED STATES PATENTS Padowicz June 21, 1949 Pitre Dec. 25, 1951 Carlston et a1 Apr. 15, 1952 

1. AN ANTI-FOULING PROTECTIVE COATING COMPOSITION COMPRISING BY WEIGHT, NON-VOLATILE INGREDIENTS COMPRISING FROM ABOUT 82% TO ABOUT 97.5% CUPROUS OXIDE, FROM ABOUT 1.7% TO ABOUT 10.5% POLYISOBUTYLENE POLYMER OF MOLECULAR WEIGHT FROM ABOUT 80,000 TO ABOUT 120,000, FROM 0% TO ABOUT 15% ROSIN, AND VOLATILE INGRIDIENTS COMPRISING A SOLVENT OF FROM ABOUT 20% TO ABOUT 130% OF THE NON-VOLATILE INGREDIENTS. 